List of top Questions asked in KEAM

A satellite is orbiting the earth in a circular orbit of radius R. Which one of the following statements is true ?

A radio transmitter sends out 60 W of radiation. Assuming that the radiation is uniform on a sphere with the transmitter at its centre, the intensity (in W/m\(^2\)) of the wave at a distance 12 km is

The magnitude of a magnetic field at the centre of a circular coil of radius R, having N turns and carrying a current I can be doubled by changing

In the given circuit P and Q form the inputs. The output $Y$ is

Consider a system of gas of a diatomic molecule in which the speed of sound at $0^\circ\text{C}$ is 1260 $\text{ms}^{-1}$. Then, the molecular weight of the gas is (Given the gas constant $R=8.314\,\text{J mol}^{-1}\text{K}^{-1}$)

Consider a cylindrical conductor of length $L$ and area of cross section $A$. The specific conductivity varies as $\sigma(x)=\sigma_0\frac{L}{\sqrt{x}}$ where $x$ is the distance along the axis of the cylinder from one of its ends. The resistance of the system along the cylindrical axis is

Three variable Boolean expression $PQ+PQR+\bar{P}Q+\bar{P}\bar{Q}R$ can be written as

A prism is made up of material of refractive index $\sqrt{2}$. The angle of the prism is $A$. If the angle of minimum deviation is equal to the angle of the prism, the value of $A$ is

If the emission rate of blackbody at $0^\circ\text{C}$ is $R$ then, the rate of emission at $273^\circ\text{C}$ is

For any material, if R, T and A represent the reflection coefficient, transparent coefficient and absorption coefficient respectively, then, for a blackbody which one of the following is true ?

Two particles A and B of same mass have their total energies $E_A$ and $E_B$ in the ratio $E_A : E_B = 1 : 2$. Their potential energies $U_A$ and $U_B$ are in the ratio $U_A : U_B = 1 : 2$. If $\lambda_A$ and $\lambda_B$ are their de Broglie wavelengths, then $\lambda_A : \lambda_B$ is

An electron is moving with a velocity $2 \times 10^6$ m/s along positive $x$-direction in the uniform electric field of $8 \times 10^7$ V/m applied along positive $y$-direction. The magnitude and direction of a uniform magnetic field (in Tesla) that will cause the electrons to move undeviated along its original path is

The electrical conductivity of a metal is

The 6 V Zener diode shown in figure has negligible resistance and a knee current of 5 mA. The minimum value of $R$ (in $\Omega$) so that the voltage across it does not fall below 6 V is

What is the minimum thickness (in nm) of a soap film ($n = 1.3$) that results in constructive interference in reflected light if the film is illuminated with light whose wavelength in free space is 620 nm?

A 2 MeV neutron is emitted in a fission reactor. If it loses half of its kinetic energy in each collision with a moderator atom, how many collisions must it undergo to achieve thermal energy of 0.039 eV?

A point charge $+Q$ is held at rest at a point $P$. Another point charge $-q$, whose mass is $m$, moves at a constant velocity $v$ in a circular orbit of radius $R_1$ around $P$. The work required to increase the radius of revolution of $-q$ from $R_1$ to another orbit $R_2$ is ($R_2 > R_1$)

A rectangular conducting loop of length $4\sqrt{2}$ m and breadth 4 m carrying a current of 5 A in the anti-clockwise direction is placed in the $xy$-plane. The magnitude of the magnetic induction field vector $B$ at the intersection of the diagonals is (Use $\mu_0=4\pi\times10^{-7}\,\text{NA}^{-2}$)

A particle of charge $Q$ moves with a velocity $\vec{v}=a\hat{i}$ in a magnetic field $\vec{B}=b\hat{j}+c\hat{k}$, where $a, b$ and $c$ are constants. The magnitude of the force experienced by the particle is

A voltage $V_{PQ}=V_0\cos\omega t$ is applied between the points P and Q in the network shown. $C=\frac{1}{\omega R\sqrt{3}}$ and $L=\frac{R\sqrt{3}}{\omega}$. The total impedance between P and Q is

Three point charges $4q$, $Q$ and $q$ are placed in a straight line of length $L$ at points 0, $L/2$ and $L$ respectively. The net force on charge $q$ is zero. The value of $Q$ is

The mean momentum of a nucleon in a nucleus with mass number A varies as

A wire made of aluminium having resistivity $\rho=2.8\times10^{-8}\,\Omega\text{ m}$ with a circular cross section and has a radius of $2\times10^{-3}$ m. A current of 5 A flows through the wire. If the voltage difference between the ends is 1 V, what is the length of the wire in meters?

A flat mirror revolves at a constant angular velocity making $n=0.4$ revolutions per second. With what velocity (in $\text{ms}^{-1}$) will a light spot move along a spherical screen with a radius of 15 meters, if the mirror is at the centre of curvature of the screen

When two capacitors are connected in parallel the resulting combination has capacitance 10 $\mu$F. The same capacitors when connected in series results in a capacitance 0.5 $\mu$F. The respective values of individual capacitors are